Comorbidity In A Clinical Sample Of Substance Abusers

Comorbidity In A Clinical Sample Of Substance Abusers

Anne Helene Skinstad

The presence of comorbid psychopathology in substance abusers is of considerable clinical interest. Psychiatric illness may serve as a risk factor for substance abuse, develop as a result of chronic substance abuse, or alter the course, prognosis, and outcome of substance abuse. Personality disorders (PD), in particular, have been associated with poorer treatment response in alcohol dependent (1-3) and drug dependent patients (4,5).

Both epidemiological and clinical studies document high rates of comorbidity linking substance abuse and PD (6). Thus, estimates of rates of PD in cocaine abusers range from 30 to 75% in inpatient samples (7-9); 68%-80% of opiate abusers have been diagnosed with additional Axis II diagnoses (10,11). Nace, Davis, and Gaspari (12) reported a 57% comorbidity rate of PD in a heterogeneous substance abuse sample. Approximately 90% percent of poly substance abusers typically receive PD diagnoses (13,14).

Elevated rates of substance abuse in PD populations have also been reported, most frequently with Cluster B PDs (15,16). Cluster B PDs, according to DSM-III-R (18), include antisocial PD, borderline PD, histrionic PD, and narcissistic PD. Cluster A PDs include paranoid PD, schizoid PD, and schizotypal PD; Cluster C PDs include avoidant PD, dependent PD, and obsessive-compulsive PD.

Antisocial PD has been consistently linked to alcoholism (19), with comorbidity estimates ranging from 15% to 50% (11-13). Antisocial PD in alcoholics is associated with early onset problem drinking, chronicity of abuse/dependence, and a greater number of alcohol related disorders (21,22).

Borderline PD has been identified in approximately 13%-18% of alcohol dependent patients (3,12,23), although higher estimates also have been reported from 28% (24) to 34% (8). Substance abusers with borderline PD tend to be younger, to have made more suicide attempts, to demonstrate more pronounced psychological problems, and to be at great risk to abuse other substances (24-26). Elevated rates of other PDs and substance abuse have also been reported (3, 8).

Many studies have focused on comorbid psychiatric disorders in substance abusing populations (27). Elevated rates of depression and anxiety disorders have been consistently documented in alcoholic samples (28,29), although prevalence rates for other acute psychiatric disorders appear to be comparable with those found in the general population, except for schizophrenia (15). Relationships between Axis I and Axis II disorders in substance abusing populations have yet to be examined.

An increasing number of patients have been diagnosed with polysubstance abuse over the last decade (30,31). However, little attention has been paid to differences between patients abusing alcohol and those who abuse other drugs (32). Addictive behaviors are similar across substances abused (33), and Harrell, Honaker, and Davis (34) found similar behavioral, physiological, interpersonal, cognitive, and emotional problems among alcoholic and polysubstance dependent patients. However, other studies have noted more psychopathology among polysubstance abusers (35-37). For instance, cocaine and alcohol dependent patients showed significantly more depression and anxiety and were more likely to receive comorbid diagnoses of antisocial PD and avoidant PD than patients dependent only on cocaine (38).

The primary purpose of this investigation was to examine the prevalence of comorbid psychiatric disorder in a group of male substance dependent subjects. We compared three subgroups of these subjects, those who were also diagnosed with borderline PD, antisocial PD, or schizoid PD, with each other as well as with a fourth subgroup without coexisting PD (NoPD) on demographic characteristics, Axis I psychopathology, and signs and symptoms of substance dependence, hypothesizing that subjects meeting criteria for borderline PD would have a higher risk of meeting criteria for other Axis I and II disorders than those meeting criteria for antisocial PD, schizoid PD, or NoPD (25,26). Finally, we compared comorbidity in alcohol-only and polysubstance dependent subjects, hypothesizing that polysubstance dependent subjects would show more Axis I and Axis II psychopathology than subjects dependent only on alcohol.

METHODS

Subjects

Subjects were 125 male inpatients admitted to one of two substance abuse treatment centers in Iowa from January to May 1994 and from August to December, 1995. Demographic characteristics for the sample are presented in Table 1. There were no significant differences in demographic characteristics between this sample and patients admitted to the same institutions during the data collection period. Iowa is ethnically a homogeneous state, and the vast majority of the sample were Caucasians.

Table 1. Demographic Characteristics of Entire Sample (N = 125)

Prevalence

Characteristic M (SD) N (%)

Age 29.48 (7.0)

Race

Caucasian 105 (84.0%)

African-American 12 (9.6%)

American Indian 3 (2.4%)

Hispanic 5 (4.0%)

Marital status

Single 79 (63.2%)

Married 15 (12.0%)

Cohabitating 5 (4.0%)

Separated 9 (7.2%)

Divorced 16 (12.8%)

Widowed 1 (0.8%)

Occupation

Student 8 (6.4%)

None 33 (26.4%)

Professional/managerial 10 (8.0%)

Sales/clerical 5 (4.0%)

Crafts/operatives 13 (10.4%)

Laborer 48 (38.4%)

Farm owner/worker 1 (0.8%)

Service/household 7 (5.6%)

Military Status

None 103 (82.4%)

Veteran 21 (16.8%)

Reserves 1 (0.8%)

Education 12.06 (1.9)

Monthly income 470.47 (817.7)

Number of previous admissions 1.49 (1.9)

Months since last discharge 20.39 (32.9)

Number of arrests over last year 1.21 (1.5)

Drunk driving .36 (0.7)

Non-drug related crime

Committed while intoxicated .27 (0.7)

Non-drug related crime

Committed while sober .25 (0.7)

Drug-related crime .50 (1.3)

Instruments

Diagnostic Interview Schedule Screening Interview-Quick DIS Version

The computerized version of the Quick DIS, originally developed by Robins et al. (39), was utilized to establish a DSM-III-R (18) diagnosis. The interview is hierarchical in nature. Questions pertaining to each disorder are asked until either all criteria are surveyed or the subject meets sufficient criteria for the diagnosis. The interviewer then establishes whether the diagnosis was met within the past year or ever in his or her lifetime. The Quick-DIS has demonstrated acceptable test-retest reliability (40), especially for psychoactive substance abuse disorders (41). The concordance of the Quick-DIS and its corresponding kappa values with symptom checklists are comparable with studies of the original Diagnostic Interview Schedule (42).

Structured Interview for DSM-III-R Personality Disorders-Revised (SIDP-R)

The SIDP-R (43) is a semistructured interview for the diagnosis of DSM-III-R PDs (18). Probe questions are used to elicit information and examples from the interviewee’s life for scoring the diagnostic criteria. The SIDP-R has adequate internal consistency and test-retest reliability and high inter-rater reliability (44) in samples of adult outpatients. Agreement between PD diagnoses based on the SIDP-R and best clinical estimate of PD, based on the judgments of a panel of investigators, is only moderate ([Kappa] = .37), although it is better than estimates based on other diagnostic interviews (45). In the present investigation, inter-rater reliability for the total number of criteria met was .98. The mean interrater reliability coefficient for individual PD criteria was .83. The reliability coefficient for borderline PD was .94; for antisocial PD .97; and for schizoid PD, .98.

Substance Abuse Reporting System (SARS)

The SARS form was used to obtain demographic information on participants, including age, race, education, employment history, relationship status, treatment history, and recent criminal history. The SARS is used with every patient admitted to a substance abuse treatment center in Iowa (46).

Procedure

Subjects were recruited from two institutions that treated patients regardless of ability to pay for treatment. The goal of the sampling procedure was to yield a sample as representative of the population of male substance abusers in treatment in Iowa as possible.

Every patient consecutively admitted to two inpatient substance abuse treatment centers in Iowa was solicited for participation from January to May 1994 and from August to December 1994. Newly admitted patients were contacted during their first week in treatment, either individually or in groups, to inform them about the study and solicit their participation. When a subject agreed to participate in the study and signed an informed consent form, the subject was interviewed at least 1 week after the last intake of substances and after medical detoxification had been completed. Subjects were interviewed by means of the Diagnostic Interview Schedule Screening Interview-Quick DIS version, the SIDP-R, and the SARS.

Data Analysis

Initial statistical analyses were performed to determine prevalence of comorbid Axis I and II psychiatric disorders. As expected, the prevalence of DSMIII-R, Axis II disorders was greatest for borderline PD, antisocial PD and schizoid PD. Subsequent statistical analyses compared the three groups–Group 1 (borderline PD), group 2 (antisocial PD), and group 3 (schizoid PD)–to with group 4 (NoPD) on demographic characteristics, substance abuse pattern, and relative risk of other comorbid psychiatric disorders. Another statistical analysis compared group A, consisting of alcohol dependent subjects only, with group P, including only polysubstance dependent subjects, on relative risk of comorbid Axis I and Axis II psychiatric disorders. The statistical program used was the SPSS-X.

RESULTS

Current (i.e., within the past 12 months) and lifetime DSM-III-R Axis I and II diagnoses for the entire sample are presented in Table 2. Over one-third (36.8%) of the subjects had a history (lifetime) of anxiety disorder and 21.6% met criteria for anxiety disorder within the previous year. Similar prevalence estimates were found for mood disorders; 31% of subjects had a history of mood disorder, and 25.6% met criteria for either major depression or bipolar disorder within the previous year. Due to the low prevalence and a lack of a priori hypotheses, the following Axis I diagnoses were not considered in further analyses: somatization disorder, eating disorders, obsessions and compulsions, schizophrenia, gambling disorder, tobacco dependence, and transsexualism.

Table 2. Current(a) and Lifetime DSM-III-R Axis I Psychopathology

Prevalence (N = 125)

Current Lifetime

Disorder N (%) N (%)

Somatization disorder 1 (0.8%) 1 (0.8%)

Any anxiety disorder 27 (21.6%) 46 (36.8%)

Panic disorder 4 (3.2%) 5 (4.0%)

GAD 12 (9.6%) 13 (10.4%)

Agoraphobia 1 (0.8%) 3 (2.4%)

Social phobia 8 (6.4%) 13 (10.4%)

Specific phobia 10 (8.0%) 14 (11.2%)

PTSD 4 (3.2%) 17 (13.6%)

Any mood disorder 32 (25.6%) 39 (31.2%)

Major depression 20 (16.0%) 27 (21.6%)

Bipolar disorder 12 (9.6%) 12 (9.6%)

Obsessions 0 (0.0) 0 (0.0)

Compulsions 4 (3.2%) 6 (4.8%)

Schizophrenia 4 (3.2%) 5 (4.0%)

Any eating disorder 2 (1.6%) 2 (1.6%)

Anorexia nervosa 1 (0.8%) 1 (0.8%)

Bulimia nervosa 1 (0.8%) 1 (0.8%)

Transsexualism 1 (0.8%) 1 (0.8%)

Gambling dependence 8 (6.4%) 15 (12.0%)

Substance use disorders

Tobacco dependence 68 (54.4%) 74 (59.2%)

Alcohol abuse 1 (0.8%) 2 (1.6%)

Alcohol dependence 87 (69.6%) 102 (81.6%)

Marijuana dependence 47 (37.6%) 79 (63.2%)

Stimulant dependence 34 (27.2%) 53 (42.4%)

Sedative dependence 17 (13.6%) 24 (19.2%)

Cocaine dependence 35 (28.0%) 53 (42.4%)

Heroin dependence 6 (4.8%) 13 (10.4%)

PCP dependence 12 (9.6%) 36 (28.8%)

Inhalant dependence 4 (3.2%) 7 (5.6%)

GAD, generalized anxiety disorder; PTSD, post-traumatic

stress disorder.

(a) Within the previous year.

Frequencies of Axis II diagnoses are presented in Table 3. The most frequent PD diagnosed among the Cluster A PDs was schizoid PD; among Cluster B were antisocial PD and borderline PD; and among Cluster C was avoidant PD. A substantial amount of Axis II comorbidity was evident.

Table 3. DSM-III-R Axis II Psychopathology

Prevalence

(N = 125)

Personality Disorder n (%)

Any Cluster A disorder 27 (21.6%)

Paranoid 8 (6.4%)

Schizoid 18 (14.4%)

Schizotypal 3 (2.4%)

Any Cluster B disorder 52 (41.6%)

Antisocial 31 (21.8%)

Borderline 17 (13.6%)

Histrionic 15 (12.0%)

Narcissistic 12 (9.6%)

Any Cluster C disorder 38 (30.4%)

Dependent 8 (6.4%)

Avoidant 18 (14.4%)

Obsessive-compulsive 12 (9.6%)

Passive-aggressive 14 (10.4%)

Any provisional diagnosis 3 (2.4%)

Sadistic 0 (0.0%)

Self-defeating 3 (2.4%)

A summary of Axis II comorbidity and the number of PDs diagnosed for individual subjects is presented in Table 4. Thirty-nine percent of the subjects failed to meet criteria for any PD, and 26.4% met criteria for one PD. However, over half of the subjects who received one PD diagnosis met criteria for a second one. Among subjects diagnosed with borderline PD, the most frequently diagnosed additional PDs were avoidant PD, antisocial PD, and dependent PD. In the antisocial PD group, subjects also frequently met criteria for avoidant PD, narcissistic PD, and borderline PD. Half the schizoid PD group did not meet criteria for any other PD diagnosis; the most frequently diagnosed additional PDs in this group were obsessive-compulsive PD and antisocial PD.

Table 4. Number of DSM-III-R Axis

II Personality Disorders Diagnosed

Prevalence

No. of Personality (N = 125)

Disorders Diagnosed n (%)

0 49 (39.2%)

1 33 (26.4%)

2 22 (17.6%)

3 14 (11.2%)

4 4 (3.2%)

7 2 (1.6%)

9 1 (0.8%)

Given the prevalence estimates and our goals for the present study, to study substance abuse across the PDs, the sample was divided into four discrete groups based on the presence or absence of particular PDs. Group 1 consisted of nine patients diagnosed with borderline PD; they did not meet criteria for either antisocial PD or schizoid PD. Group 2 comprised 22 patients who had been diagnosed with antisocial PD; they had not been diagnosed with either borderline PD or schizoid PD. Group 3 included 13 patients who met criteria for schizoid PD; they had not met criteria for either borderline PD or antisocial PD. The fourth group (NoPD) consisted of the 49 remaining subjects who failed to meet criteria for any PDs. No other nonoverlapping, sufficiently sizeable groups of patients meeting the criteria for a particular PD could be formed.

Acute Psychopathology Across Personality Disorder Subtypes

Current (i.e., within-the-past-12-months) and lifetime diagnoses of mood and anxiety disorders were compared across PD groups. Frequencies of current diagnoses for each group are presented in Table 5. Patients diagnosed with borderline PD showed the highest rate of comorbid psychopathology. They were significantly more likely to receive diagnoses of specific phobia [continuity corrected [chi square] (3) = 8.59; p [is less than] .05], generalized anxiety disorder [continuity corrected [chi square] (3) = 12.06; p [is less than] .001], and major depressive disorder [continuity corrected [chi square] (3) = 11.27; p [is less than] .01]. Subjects with antisocial PD were more likely to receive a diagnosis of bipolar disorder [continuity corrected [chi square] (3) = 9.37; p [is less than] .05]. Comparisons of lifetime diagnoses were similar. Patients diagnosed with borderline PD were significantly more likely to receive lifetime diagnoses of any anxiety disorder [continuity corrected [chi square] (3) = 22.94; p [is less than] .0001], specific phobia [continuity corrected [chi square] (3) = 8.22; p [is less than] .05], generalized anxiety disorder [continuity corrected [chi square] (3) = 10.80; p [is less than] .01], and major depressive disorder [continuity corrected [chi square] (3) = 9.38; p [is less than] .05]. Subjects in the antisocial PD group were more likely to receive lifetime diagnoses of bipolar affective disorder [continuity corrected [chi square] (3) = 9.38; p [is less than] .05].

Table 5. Current DSM-III-R Axis I Psychopathology Across Personality

Disorder Groups

Borderline Antisocial

Personality Personality

Disorder Disorder

(N = 9) (N = 22)

Axis I Disorder n (%) n (%)

Any anxiety disorder 5 (55.6%) 3 (13.6%)

Panic disorder 2 (22.2%) 0 (0)

GAD 4 (44.4%) 2 (9.1%)

Agoraphobia 1 (11.1%) 1 (4.5%)

Social phobia 2 (22.2%) 0 (0)

Specific phobia 4 (44.4%) 1 (4.5%)

PTSD 3 (33.3%) 3 (13.6%)

Any mood disorder 5 (55.6%) 7 (31.8%)

Major depression 5 (55.6%) 2 (9.1%)

Bipolar disorder 0 (0) 5 (22.7%)

Substance use disorders

Alcohol dependence 7 (77.8%) 18 (81.8%)

Marjiuana dependence 7 (87.5%) 14 (73.7%)

Stimulant dependence 5 (62.5%) 10 (52.6%)

Sedative dependence 3 (37.5%) 3 (15.8%)

Cocaine dependence 6 (75.0%) 9 (47.4%)

Heroin dependence 1 (12.5%) 2 (10.5%)

PCP dependence 5 (62.5%) 6 (31.6%)

Inhalant dependence 3 (37.5%) 0 (0)

Schizoid No

Personality Personality

Disorder Disorder

(N = 13) (N = 49)

Axis I Disorder n (%) n (%)

Any anxiety disorder 2 (15.4%) 7 (14.3%)

Panic disorder 0 (0) 2 (4.1%)

GAD 0 (0) 3 (6.1%)(a)

Agoraphobia 0 (0) 0 (0)

Social phobia 2 (15.4%) 4 (8.2%)

Specific phobia 1 (7.7%) 4 (8.2%)(b)

PTSD 1 (7.7%) 5 (10.2%)

Any mood disorder 3 (23.1%) 6 (12.2%)(b)

Major depression 3 (23.1%) 4 (8.2%)(a)

Bipolar disorder 0 (0) 2 (4.1%)(b)

Substance use disorders

Alcohol dependence 13 (100%) 39 (79.6%)

Marjiuana dependence 6 (50.0%) 29 (65.9%)

Stimulant dependence 5 (41.7%) 16 (36.4%)

Sedative dependence 3 (25.0%) 7 (15.9%)

Cocaine dependence 2 (16.7%) 17 (38.6%)(b)

Heroin dependence 2 (16.7%) 5 (11.4%)

PCP dependence 2 (16.7%) 11 (25.0%)

Inhalant dependence 1 (8.3%) 0 (0)(b)

GAD, generalized anxiety disorder; PTSD, post-traumatic stress disorder.

(a) p < .01.

(b) p < .05.

Polysubstance Dependence and Psychopathology on Axes I and II

Polysubstance dependent subjects were compared with the remainder of the sample for risk of current Axis I psychopathology (Table 6). Polysubstance dependent subjects showed more comorbidity and were significantly more likely to have been diagnosed within the past 12 months with specific phobia [continuity corrected [chi square](1) = 4.51; p [is less than] .05] and bipolar affective disorder [continuity corrected [chi square](1) = 11.79; p [is less than] .001]. Unsurprisingly, they were also at higher risk for dependence on marijuana, stimulants, sedatives, cocaine, heroin, and PCP. Examination of lifetime prevalence estimates of Axis I disorders yielded similar results. Table 6 summarizes the relative risk of Axis I psychopathology in polysubstance and nonpolysubstance dependent subjects.

Table 6. Current DSM-III-R Axis I Psychopathology and Relative Risk in

Polysubstance Dependent and Nonpolysubstance Dependent Subjects

Poly- Nonpoly-

substance substance

Dependent Dependent

(N = 43) (N = 82) Relative

Disorder n (%) n (%) Risk

Any anxiety disorder 13 (30.2%) 14 (17.1%) 1.57

Panic disorder 2 (4.7%) 2 (2.4%) 1.48

GAD 5 (11.6%) 7 (8.5%) 1.24

Agoraphobia 1 (2.3%) 0 (0)

Social phobia 4 (9.3%) 4 (4.9%) 1.50

Specific phobia 7 (16.3%) 3 (3.7%)(a) 2.24

PTSD 2 (4.7%) 2 (2.4%) 1.48

Any mood disorder 18 (41.9%) 14 (17.1%)(b) 2.45

Major depression 8 (18.6%) 12 (14.6%) 1.28

Bipolar disorder 10 (23.3%) 2 (2.4%)(c) 9.53

Substance use disorders

Alcohol dependence 28 (65.1%) 59 (72.0%)(c) 0.82

Marijuana dependence 33 (88.4%) 14 (20.6%) 8.62

Stimulant dependence 28 (65.1%) 6 (8.8%)(c) 4.23

Sedative dependence 17 (39.5%) 0 (0)(c)

Cocaine dependence 25 (58.1%) 10 (14.7%)(c) 3.02

Heroin dependence 5 (11.6%) 1 (1.5%)(a) 2.30

PCP dependence 12 (27.9%) 0 (0)(c)

Inhalant dependence 4 (9.3%) 0 (0)(b)

GAD, generalized anxiety disorder; PTSD, post-traumatic stress

disorder.

(a) p < .05.

(b) p < .01.

(c) p < .001.

Personality disorders displayed by polysubstance and nonpolysubstance dependent subjects are shown in Table 7. Polysubstance dependent subjects were more likely to be diagnosed with a Cluster B PD than nonpolysubstance dependent subjects [continuity corrected [chi square] (1) = 4.60; p [is less than] .05]. Specifically, they were more likely to be diagnosed with histrionic PD [continuity corrected [chi square] (1) = 3.75; p [is less than] .05] or borderline PD [continuity corrected [chi square] (1) [is less than] 4.02; p [is less than] .05]. Additionally, polysubstance dependent subjects were more likely to meet criteria for the Cluster C PD, dependent PD [continuity corrected [chi square](1) = 4.47; p [is less than] .05].

Table 7 DSM-III-R Personality Disorders and Relative Risk in

Polysubstance Dependent and Nonpolysubstance Dependent Subjects

Poly- Nonpoly-

substance substance

Dependent Dependent

(N = 43) (N = 82) Relative

Personality Disorder n (%) n (%) Risk

Any Cluster A disorder 10 (23.3%) 17 (20.7%) 1.12

Paranoid 4 (9.3%) 5 (5.8%) 1.37

Schizoid 6 (14.0%) 12 (14.0%) 1.00

Schizotypal 1 (2.3%) 2 (2.3%) 1.00

Any Cluster B disorder 24 (55.8%) 28 (34.1%)(a) 1.63

Antisocial 15 (34.9%) 17 (19.8%) 1.62

Borderline 10 (23.3%) 7 (8.1%)(a) 2.00

Histrionic 9 (20.9%) 6 (7.0%)(a) 2.01

Narcissistic 7 (16.3%) 5 (5.8%) 1.90

Any Cluster C disorder 17 (39.5%) 21 (25.6%) 1.54

Dependent 6 (14.0%) 2 (2.3%)(a) 2.45

Avoidant 9 (20.9%) 9 (10.5%) 1.63

Obsessive-compulsive 3 (7.0%) 9 (10.5%) 0.73

Passive-aggressive 5 (11.6%) 9 (10.5%) 1.08

Any provisional diagnosis 3 (7.0%) 0 (0)

Sadistic 0 (0) 0 (0)

Self-defeating 3 (7.0%) 0 (0)

(a) p < .05.

Alcoholics and Axis I and II Psychopathology

Similarly, subjects dependent on alcohol only were compared with the remainder of the sample for risk of current and lifetime Axis I and II psychopathology (Tables 8 and 9). Few differences were found. With statistical corrections for multiple comparisons, no differences were significant between alcohol dependent only subjects and the remainder of the sample. Nevertheless results suggest trends for less psychopathology in the alcoholic dependent only subgroup.

Table 8. Current DSM-III-R Axis I Psychopathology and Relative

Risk in Al Dependent Only and Nonalcohol Dependent Only

Alcohol

Dependent Nonalcohol

Only Dependent

(N = 22) (N = 103) Relative

Disorder n (%) n (%) Risk

Any anxiety disorder 3 (13.6%) 24 (23.3%) 0.57

Panic disorder 1 (4.5%) 3 (2.9%) 1.44

GAD 1 (4.5%) 11 (10.7%) 0.45

Agoraphobia 0 (0) 1 (1.0%)

Social phobia 1 (4.5%) 7 (6.8%) 0.70

Specific phobia 1 (4.5%) 9 (8.7%) 0.55

PTSD 1 (4.5%) 3 (2.9%) 1.44

Any mood disorder 5 (22.7%) 27 (26.2%) 0.87

Major depression 5 (22.7%) 15 (14.6%) 1.56

Bipolar disorder 0 (0) 12 (11.7%) 1.13

Substance use disorders

Alcohol dependence 20 (90.9%) 67 (65.0%)(a) 4.37

GAD, generalized anxiety disorder; PTSD, post-traumatic stress

disorder.

(a) p < .01.

Table 9. DSM-III-R Personality Disorders and Relative Risk in

Alcohol Dependent Only and Nonalcohol Dependent Subjects

Alcohol

Dependent Nonalcohol

Only Dependent

(N = 22) (N = 103) Relative

Personality Disorder n (%) n (%) Risk

Any Cluster A disorder 5 (22.7%) 22 (21.4%) 1.06

Paranoid 0 (0) 9 (8.4%)

Schizoid 5 (22.7%) 13 (12.1%) 1.81

Schizotypal 0 (0) 3 (2.8%)

Any Cluster B disorder 5 (22.7%) 47 (45.6%) 0.50

Antisocial 2 (9.1%) 30 (28.0%) 0.30

Borderline 1 (4.5%) 16 (15.0%) 0.31

Histrionic 2 (9.1%) 13 (12.1%) 0.76

Narcissistic 2 (9.1%) 10 (9.3%) 0.98

Any Cluster C disorder 6 (27.3%) 32 (31.1%) 0.88

Dependent 0 (0) 8 (7.5%)

Avoidant 4 (18.2%) 14 (13.1%) 1.37

Obsessive-compulsive 2 (9.1%) 10 (9.3%) 0.98

Passive-aggressive 2 (9.1%) 12 (11.2%) 0.82

Any provisional diagnosis 0 (0) 3 (2.9%)

Sadistic 0 (0) 0 (0)

Self-defeating 0 (0) 3 (2.8%)

DISCUSSION

Iowa is homogeneous ethnically, and our clinical sample reflects this fact. Most members of this sample were Caucasian. However, the prevalence of subjects from minority groups was higher than in the General Household Survey (47), a Substance Abuse Treatment Needs Assessment Survey with a representative sample from all 99 counties in Iowa, completed using a random digit dial method for data collection. This clinical sample was drawn from two institutions, one of which recruited patients from the Des Moines metropolitan area, which is generally more diverse than other parts of Iowa. Several subjects in this sample lived alone, had no partner, were unmarried or divorced, and were unemployed, social situations often related to poor treatment prognosis (48).

Alcohol is the most frequently reported substance used and abused in the general population of Iowa, followed by marijuana, cocaine, other stimulants, sedatives, PCP, heroin, and inhalants (47,49). Data from this clinical sample confirm the pattern of substance abuse and dependence found in the Adult Household Study (47). A substantial increase in crystal methamphetamine abuse and dependence has been reported since this study was completed (50). Gambling has become an increasing problem in Iowa. About 7% in this sample met criteria for gambling dependence within the past 12 months; the corresponding lifetime rate was 12%.

Polysubstance dependence was reported in over one-third of the sample, and alcohol was commonly used in combination with another substance. This pattern of substance dependence has frequently been reported in clinical samples (30), with relatively few patients abusing alcohol only. Instead they use alcohol in combination with other substances. Only 17.6% of this clinical sample were dependent on alcohol only, whereas 48% of the subjects met criteria for dependence on substances other than alcohol.

Patients treated for Axis 1 psychiatric disorders have commonly had coexisting substance dependence (27,51). Likewise, patients treated for substance dependence frequently report comorbid psychiatric disorders, such as mood (28,29) and anxiety disorders (27), with substance dependent women meeting criteria for such disorders significantly more often than men (52). This study identified a large number of substance dependent males meeting DSM-III-R (18) criteria for mood disorder, especially major depression. Furthermore, many met criteria for anxiety disorders.

Axis II PDs and substance abuse disorders are commonly comorbid (6). Over half the sample met criteria for from one to three PDs; one subject met criteria for nine. Nace, Davis, and Gaspari (12) reported 57% of substance abusers meeting criteria for a PD. Miller and Fine (15) reported Cluster B PD to be the most frequently diagnosed PDs in a group of substance dependent subjects. Our study confirms these results in that Cluster B PDs (such as antisocial PD and borderline PD were the most frequently diagnosed PDs in this sample, followed by Cluster C avoidant PD, passive-aggressive PD, and obsessive-compulsive PD. Schizoid PD was the most frequently diagnosed Cluster A PD. Even though these results indicate a high number of subjects meeting criteria for a DSM-III-R (18) diagnosis of PD, more than 40% of the sample did not meet criteria for any PD diagnosis.

Previous studies have been inconclusive regarding the level of psychopathology shown in polysubstance dependent subjects (34,35). Results from this study support the hypothesis that polysubstance dependent subjects would meet criteria for more Axis I and II disorders than subjects dependent on only one substance. Polysubstance dependent subjects met criteria for mood disorder, especially bipolar disorders, significantly more often than three other groups. Furthermore, polysubstance dependent subjects met criteria for Cluster B PDs, including borderline PD and histrionic PD, as well as Cluster C, dependent PD, significantly more often than did nonpolysubstance dependent subjects. In comparison, the relative risk of subjects with only alcohol dependence meeting criteria for any Axis I and Axis II diagnosis was substantially lower.

Subjects meeting criteria for borderline PD seemed to be at greater risk for being diagnosed with anxiety disorders, including generalized anxiety disorder and specific phobic disorder, and mood disorders, including major depressive disorder, than patients diagnosed with antisocial PD and schizoid PD. Our results are supported by results from other studies (25,26,53). The borderline PD group met criteria for polysubstance dependence and dependence on cocaine and inhalants to a greater extent than any of the other three groups. The borderline PD group also tended to meet criteria for other comorbid PDs like avoidant PD, antisocial PD, and dependent PD, a result also reported in other studies (3,8).

The incidence of antisocial PD among alcohol dependent subjects is commonly high (13), and antisocial PD was the most frequently diagnosed PD among our subjects. These subjects exhibited a higher risk of bipolar disorder than the borderline PD, schizoid PD, and NoPD groups. Subjects with antisocial PD can be diagnosed with comorbid bipolar disorders, according to DSM-IV (54), when signs and symptoms of the two disorders are identified independently. Additionally, the antisocial PD subjects were more frequently diagnosed with comorbid PDs such as avoidant PD, narcissistic PD, and borderline PD.

Over 14% of the sample met criteria for schizoid PD, which is high in a sample of substance dependent subjects (55,56). Results from this study indicated that the schizoid PD group was less likely to be polysubstance dependent (about 23% were dependent on alcohol only); fewer of them met criteria for comorbid Axis I or II disorders, and they reported less subjective distress compared to the antisocial PD and borderline PD. Schizoid PD as a diagnostic entity has not been well described in the literature, and has often been considered as a behavioral attitude, consisting of superficial or no social contacts (56), social isolation and binge drinking (57), rather than a diagnostic entity (58).

In conclusion, this sample consisted of males only, and the results cannot be generalized to female substance dependent subjects. However, the results from our clinical sample indicate a high prevalence of comorbid Axis I and II disorders in the substance dependent subjects studied, underscoring the importance of assessing substance dependent subjects for additional psychiatric disorders in order to form a realistic treatment plan. To do so, the diagnostic process must be comprehensive. Furthermore, the timing of diagnostic assessments is crucial. Some short term and long term consequences of substance dependence mimic signs and symptoms of psychiatric disorder and will subside when the withdrawal process is completed. Treatment of subjects with comorbid substance dependence and other Axis I and II disorders is challenging, Axis II disorders, in particular, have been associated with poorer treatment responses (1). Treatment plans must be goal oriented (59) and focused on bettering the unstable living and unemployment situation (48) often found in this population.

ACKNOWLEDGMENTS

This study was supported by the Iowa Measurement Research Foundation, The University of Iowa. We are especially grateful to Prof. Emeritus Leonard Feldt for supporting this project financially and giving important advice concerning the methodology. We are also grateful to Patrice Carrello for assisting in the data collection and Ginny Travis for clerical support.

REFERENCES

(1.) Booth, B.M.; Cook, C.L.; Blow, F.C. Comorbid Mental Disorders in Patients with AMA Discharges from Alcoholism Treatment. Hosp. Community Psychiatry 1992, 43, 730-731.

(2.) Nace, E.P.; Davis, C.W. Treatment Outcome in Substance-Abusing Patients with a Personality Disorder. Am. J. Addict. 1993, 2, 26-33.

(3.) Nurnberg, H.G.; Rifkin, A.; Doddi, S. A Systematic Assessment of the Comorbidity of DSM-III-R Personality Disorders in Alcoholic Outpatients. Compr. Psychiatry 1993, 34, 447-454.

(4.) Andreoli, A.; Gressot, G.; Aapro, N.; Tricot, L.; Gognalons, M.Y. Personality Disorders as a Predictor of Outcome. J. Pers. Disord. 1989, 3, 307-320.

(5.) el-Guebaly, N. Substance Use Disorders and Mental Illness: The Relevance of Comorbidity. Can. J. Psychiatry 1995, 40, 2-3.

(6.) Helzer, J.E.; Przybeck, T.R. The Co-occurrence of Alcoholism with Other Psychiatric Disorders in the General Population and Its Impact on Treatment. J. Stud. Alcohol 1988, 49, 219-224.

(7.) Kleinman, P.H.; Miller, A.B.; Millman, R.B.; Woody, G.E.; Todd, T.; Kemp, J.; Lipton, D.S. Psychopathology Among Cocaine Abusers Entering Treatment. J. Nerv. Ment. Dis. 1990, 178, 442-447.

(8.) Kranzler, H.R.; Satel, S.; Apter, A. Personality Disorders and Associated Features in Cocaine-dependent inpatients. Compr. Psychiatry 1994, 35, 335-340.

(9.) Weiss, R.D.; Mirin, S.M.; Griffin, M.L.; Gunderson, J.G.; Hufford, C. Personality Disorders in Cocaine Dependence. Compr. Psychiatry 1993, 34, 145-149.

(10.) Kosten, T.R.; Rounsaville, B.J.; Kleber, H.D. DSM-III Personality Disorders in Opiate Addicts. Compr. Psychiatry 1982, 23, 572-581.

(11.) Malow, R.M.; West, J.A.; Williams, J.L.; Sutker, P.B. Personality Disorders Classification and Symptoms in Cocaine and Opioid Addicts. J. Consult. Clin. Psychol. 1989, 57, 765-767.

(12.) Nace, E.P.; Davis, C.W.; Gaspari, J.P. Axis II Comorbidity in Substance Abusers. Am. J. Psychiatry 1991, 148, 118-120.

(13.) DeJong, C.A.; van den Brink; W., Hartevedt, F.M.; van der Wielen, E.G. Personality Disorders in Alcoholics and Drug Addicts. Compr. Psychiatry 1993, 34, 87-94.

(14.) Lewis, C.E.; Rice, J.; Helzer, J.E. Diagnostic Interactions: Alcoholism and Antisocial Personality. J. Nerv. Ment. Dis. 1983, 171, 105-113.

(15.) Miller, N.S.; Fine, J. Current Epidemiology of Comorbidity of Psychiatric and Addictive Disorders. Psychiatr. Clin. North Am. 1983, 16, 1-10.

(16.) Mors, O.; Sorensen, L.V. Incidence and Comorbidity of Personality Disorders Among First Ever Admitted Psychiatric Patients. Eur. Psychiatry 1994, 9, 175-184.

(17.) Samuels, J.F.; Nestadt, G.; Romanoski, A.J.; Folstein, M.F.; McHugh, P.R. DSM-III Personality Disorders in the Community. Am. J. Psychiatry 1994, 151, 1055-1062.

(18.) American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders-III Edition-Revised (DSM-III-R). American Psychiatric Association: Washington DC; 1987.

(19.) Schuckit, M. The Clinical Implications of Primary Diagnostic Groups among Alcoholics. Arch. Gen. Psychiatry 1985, 42, 1043-1049.

(20.) Ross, H.E.; Glaser, F.B.; Germanson, T. The Prevalence of Psychiatric Disorders in Patients with Alcohol and Other Drug Problems. Arch. Gen. Psychiatry 1988, 45, 1023-1031.

(21.) Cook, B.L.; Winokur, G.; Fowler, R.C.; Liskow, B.I. Classification of Alcoholism with Reference to Comorbidity. Compr. Psychiatry 1994, 35, 165-170.

(22.) Hesselbrock, V.N.; Hesselbrock, M.N.; Stabenau, J.R. Alcoholism in Men Patients Subtyped by Family History and Antisocial Personality. J. Stud. Alcohol 1985, 46, 59-64.

(23.) Mirin, S.M.; Weiss, R.S. Character Pathology in Substance Abusers. Presented at the American Psychiatric Association Annual Meeting, Montreal, May 1988.

(24.) Jonsdottir-Baldursson, T.; Horvath, P. Borderline Personality-Disordered Alcoholics in Iceland: Descriptions on Demographic, Clinical, and MMPI Variables. J. Consult. Clin. Psychol. 1987, 55, 738-741.

(25.) Bunt, G.; Galanter, M.; Lifshutz, H.; Castaneda, R. Cocaine/”Crack” Dependence Among Psychiatric Inpatients. Am. J. Psychiatry 1990, 147, 1542-1546.

(26.) Skinstad, A.H. MMPI characteristics of alcoholics with borderline personality disorder. Eur. J. Psychol. Assess. 1994, 10, 34-42.

(27.) Blow, F.C.; Cook, C.L.; Booth, B.M.; Falcon, S. P.; Friedman, M.J. Agerelated Psychiatric Comorbidities and Level of Functioning in Alcoholic Veterans Seeking Outpatient Treatment. Hosp. Community Psychiatry 1992, 43, 990-995.

(28.) Walker, R.D.; Howard, M.O.; Lambert, M.D.; Suchinsky, R. Psychiatric and Medical Comorbidities of Veterans with Substance Use Disorders. Hosp. Community Psychiatry, 1994, 45, 232-237.

(29.) Penick, E.C.; Powell, B.J.; Nickel, E.J.; Bingham, S.F.; Riesenmy, K.R.; Read, M.R.; Campbell, J. Co-Morbidity of Lifetime Psychiatric Disorder among Male Alcoholic Patients. Alcohol. Clin. Exp. Res. 1994, 18, 1289-1293.

(30.) Abellanas, L.; McLellan, A.T. “Stage of Change” by Drug Problem in Concurrent Opiate, Cocaine, and Cigarette Users. J. Psychoactive Drugs 1993, 25, 307-313.

(31.) Miller, N.S.; Mirin, S.M. Multiple Drug Use in Alcoholics: Practical and Theoretical Implications. Psychiatr. Ann. 1989, 19, 251-255.

(32.) Brown, T.G.; Fayek, A. Comparison of Demographic Characteristics and MMPI Scores from Alcohol and Poly-Drug, Alcohol, and Cocaine Abusers. Alcohol Treat. Q. 1993, 19, 123-135.

(33.) Donovan, D.M. Assessment of Addictive Behaviors: Implications of an Emerging Biopsychosocial Model. In Assessment of Addictive Behaviors; Donovan, D.M., Marlatt, G.A., Eds.; Guilford Press: New York, 1988; 3-48.

(34.) Harrell, T.H.; Honaker, L.M.; Davis, E. Cognitive and Behavioral Dimensions of Dysfunction in Alcohol and Polydrug Abusers. J. Subst. Abuse 1991, 3, 415-426.

(35.) Kennedy, B.; Konstantareas, M.; Homatidis, S. A Behavioral Profile of Polydrug Abusers. J. Youth Adolesc. 1987, 16, 115-127.

(36.) O’Boyle, M. Personality Disorder and Multiple Substance Dependence. J. Pers. Disord. 1993, 7, 342-347.

(37.) O’Boyle, M.; Barratt, E.S. Impulsivity and DSM-III-R Personality Disorders. Pers. Individ. Diff. 1993, 14, 609-611.

(38.) Cunningham, S.C.; Corrigan, S.A.; Malow, R.M.; Smason, I.H. Psychopathology in Inpatients Dependent on Cocaine or Alcohol and Cocaine. Psychol. Addict. Behav. 1993, 7, 246-250.

(39.) Robins, L.N.; Helzer, J.E.; Croughan, J.; Ratcliff, K.S. National Institute of Mental Health Diagnostic Interview Schedule: Its History, Characteristics and Validity. Arch. Gen. Psychiatry 1981, 38, 381-389.

(40.) Blouin, A.G.; Perez, E.L.; Blouin, J.H. Computerized Administration of the Diagnostic Interview Schedule. Psychiatry Res. 1988, 23, 335-344.

(41.) Ross, H.E.; Swinson, R.; Doumani, S.; Larkin, E.J. Diagnosing Comorbidity in Substance Abusers: A Comparison of the Test-Retest Reliability of Two Interviews. Am. J. Drug Alcohol Abuse 1995, 21, 167-185.

(42.) Levitan, R.D.; Blouin, A.G.; Navarro, J.R.; Hill, J. Validity of the Computerized DIS for Diagnosis of Psychiatric Inpatients. Can. J. Psychiatry 1991, 36, 728-731.

(43.) Pfohl, B.; Blum, N.; Zimmerman, M.; Stangl, D. Structural Interview for DSM-III-R Personality SIDP-R. The University of Iowa: Iowa City, 1989.

(44.) Nazikian, H.; Rudd, R.P.; Edwards, J.; Jackson, H.J. Personality Disorder Assessment for Psychiatric Inpatients. Aust. N. Z. J. Psychiatry 1990, 24, 37-46.

(45.) Pilkonis, P.A.; Heape, C.L.; Proietti, J.M.; Clark, S.W.; McDavid, J.D.; Pitts, T.E. The Reliability and Validity of Two Structured Diagnostic Interviews for Personality Disorders. Arch. Gen. Psychiatry 1995, 52, 1025-1033.

(46.) Cadoret, R.J.; Abbott, E. Factors Affecting Evaluation of Treatment Outcome in State-Funded Substance Abuse Treatment Programs: A Preliminary Analysis; Iowa Consortium on Substance Abuse Research and Evaluation, Iowa Department of Public Health, Division of Substance Abuse and Health Promotion: Des Moines, Iowa, 1993.

(47.) Lutz, G.M.; Kramer, R.E.; Crew, B.K.; Larz, G.L.; Turner, T.M. Iowa 1993 Adult Household Survey of Substance Use and Treatment Needs; Center for Social and Behavioral Research, The University of Northern Iowa and the Iowa Consortium of Substance Abuse Research and Evaluation, University of Iowa, 1994.

(48.) Bromet, E.; Moos, R.H. Environmental Resources and the Posttreatment Functioning of Alcoholic Patients. J. Health Soc. Behav. 1977, 18, 326-338.

(49.) Skinstad, A.H.; Eliason, M.J.; Gerken, K.; Spratt, K.F.; Lutz, G.M.; Childress, K. Alcohol and Drug Abuse among Iowa Women. Iowa State Needs Assessment Project; College of Education and the Iowa Consortium on Substance Abuse Research and Evaluation, The University of Iowa, Iowa City, 1996.

(50.) Iowa Department of Public Health. Annual Report; Iowa Department of Public Health, Division of Substance Abuse and Health Promotion: Des Moines, Iowa, 1996.

(51.) Mendelson, J.H.; Babor, T.F.; Mello, N.; Pratt, H. Alcoholism and Prevalence of Medical and Psychiatric Disorder. J. Stud. Alcohol 1986, 47, 361-366.

(52.) Hill, S.Y. Mental and Physical Health Consequences of Alcohol Use in Women. In Galanter, M., Ed. Recent Developments in Alcoholism. Alcoholism and Women; Plenum Press: New York, 1995; Vol. 12, 81-197.

(53.) Stone, M.H. Borderline Personality Disorder: Course of Illness. In Borderline Personality Disorder. Clinical and Empirical Perspective; Clarkin, J.F., Marziali, E., Munroe-Blum, H., Eds.; Guilford Press: New York, 1992; 67-86.

(54.) American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th Ed.; American Psychiatric Association: Washington, DC, 1994.

(55.) Costello, R.M. Schizoid Personality Disorder: A Rare Type in Alcoholic Populations. J. Person. Disord. 1989, 3, 321-328.

(56.) Millon, T. Disorders of Personality; Wiley: New York, 1981.

(57.) Morey, L.C.; Skinner, H.A.; Blashfield, R.K. A Typology of Alcohol Abusers: Correlates and Implications. J. Abnorm. Psychol. 1984, 9, 408-417.

(58.) Pfohl, B. Personal conversation. University of Iowa: Iowa City, 1996.

(59.) Linehan, M.M.; Heard, H.I. Dialectic Behavior Therapy for Borderline Personality Disorder. In Borderline Personality Disorder. Clinical and Empirical Perspectives; Clarkin, J.F., Marziali, E., Munroe-Blum, H., Eds.; Guilford Press: New York, 1992; 248-267.

Anne Helene Skinstad, Ph.D.,(1),(*) and Annette Swain, Ph.D.(2)

(1) Substance Abuse Counseling Program and (2) Department of Psychology, The University of Iowa, Iowa City, Iowa

(*) Correspondence: Coordinator of the Substance Abuse Counseling Program, Program Director of the Prairielands Addiction Technology Transfer Center, The University of Iowa (N 354 Lindquist Building), Iowa City, IA 52242-1529. E-mail: anne-skinstad@ uiowa.edu

COPYRIGHT 2001 Marcel Dekker, Inc.

COPYRIGHT 2001 Gale Group